S05E111 Installing Ventilation to Prevent Condensation in a Shipping Container

We have a metal storage container at work that is so humid inside that mould is growing on the ceiling and the contents of the container are being damaged. Today I attempt to improve the venting to deal with it.
Hi there, my name is Arne and if you're new to the channel, in addition to various home DIY projects, I look after the facilities maintenance end of things at a multi-campus K-12 school (plus a Preschool & Daycare) in Langley, BC. With nearly 1300 students, 200 staff, 5 campus' and various other outbuildings, there's always something to do.
I love my job; not only does the work I do benefit many, every day brings new challenges, which keeps me on my toes and in problem-solving mode.
Stay safe and be kind to one another!

[@sandparts]

Thanks for posting this, I had ordered a solar fan I was going to install into the door to pull air in. After watching this video I cancelled the fan and ordered the whirlybird. I had thought of doing this but didn't know how I'd install on a non-flat roof. I installed exactly as you show in this video. I'm just waiting on some side vents to finish everything. Have the same exact moisture problem in mine with a moldy ceiling. I appriciate you posting this video!

[@facilitiesmaintenancebyarne]

You're welcome. Thanks for watching!

[@TinyHouseHomestead]

3D print filler blocks and seal with sealer and cover with O'Henry's! 😁👍👍🇺🇸

[@phillipgroom9187]

Watching this video made me think about how much time you put into each one. Thinking about how you will explain what you will be doing and why. Putting up pictures to help explain it. Thank you for what you do, not only for the KZbinrs but for the school. Good job ! Have a blessed day !

[@facilitiesmaintenancebyarne]

Much appreciated, Phillip. Thank you very much.

[@specialized29er86]

We put two 300mm x 300mm vents into one side of our 20 foot containers and also a solar powered whirlybird on the roof thats hard wired into the mains to continue to run during the nights. Anyone wanting to mount a whirlybird I bought 2 adaptors from Container Creations in America and they posted them to Australia.

[@facilitiesmaintenancebyarne]

I like that setup!

[@jumper553]

While it's true that mold can only grow on organic surfaces, there is undoubtedly dirt on the surface of the top of the container. And mold CAN grow on the dirt - and it doesn't take much to provide a perfect "petri dish."

[@facilitiesmaintenancebyarne]

For sure!

[@terrym6458]

Nice job as always!

[@facilitiesmaintenancebyarne]

Thanks!

[@glennduxbury2568]

Good to now not store anything at all against walls /the ceiling, to help that air-movement, as was discovered by that wooden door.

[@facilitiesmaintenancebyarne]

In a perfect world, yes, I agree. However, you and I both know that in a storage things will be stored against the walls. Now that the general humidity issues within the container have been corrected, stuff that was stored against the walls will (hopefully) no longer have issues. The walls are built with natural grooves, which help facilitate circulation behind things, so it’s not like the back of a closet with zero air circulation. I also have another theory. We have been storing ice-melt inside the container, and ice-melt is a desiccant so it has been drawing moisture into the container. I have a feeling that if this ice-melt were not in the container in the first place, the issue would not have been as severe.

[@PARK84.]

Hi. I'm wondering, Arne Larsen is a typical Scandinavian name, not everyday I hear that name in Canada. 😊

[@facilitiesmaintenancebyarne]

Haha… very true. My family is from 🇳🇴

[@PARK84.]

@@facilitiesmaintenancebyarne ohh wow. I'm from Norway too. Do you know where in Norway? 👍

[@jeffreysteinkamp4042]

I am wondering how the ventilation problem turned out with the increased vents and spiral vent on the roof. Did you achieve your results of no water and mold on the interior walls

[@facilitiesmaintenancebyarne]

Much improved. Part of the problem is that we store ice-melter in this container, which is a desiccant and attracts water. If we didn't do this the issue would be completely eliminated.

[@JoeTheBlacksmith13]

⁠@@facilitiesmaintenancebyarne they actually use desiccants to absorb water and keep humidity down. They sell hanging bags of calcium chloride to absorb water and reduce humidity in shipping containers.

[@facilitiesmaintenancebyarne]

@@JoeTheBlacksmith13 the same concept as a similar product they make for off-season RV/camper storage. Thanks for watching.

[@JoeTheBlacksmith13]

@@facilitiesmaintenancebyarne right. So if that de-icer is a desiccant, it should be helping to reduce moisture in the air, not make matters worse. Thanks for sharing your experience.

[@facilitiesmaintenancebyarne]

I know… weird, right? Anyways, not a scientific controlled comparison as we’ve never NOT stored the ice melter in the container so I can’t say for certain whether removing it would change anything.

[@klugkluk]

Quite the opposite of a leak, yet you still wound up on a roof 😂

[@facilitiesmaintenancebyarne]

Good point... lol.

[@sherbitdab4767]

How did it work did this solve the issue thx

[@facilitiesmaintenancebyarne]

Much improved. Part of the problem is that we store ice-melter in this container, which is a desiccant and attracts water. If we didn't do this the issue would be completely eliminated.

[@jessiemartinez7681]

did you make a video for an update?

[@facilitiesmaintenancebyarne]

No, I haven't but the situation was improved by the venting.

[@naterchapman1871]

why would you only cut a small rectangle? just cut the entire dam hole out, air is liquid like water, only so much will go through that hole at once, bigger opening means more air flow.

[@facilitiesmaintenancebyarne]

Two reasons: "Small" is relative. The limiting factor in a convection system will be the smallest opening(s). The hole in the roof is 4" x 13", which is 52 square inches... which is greater than the combined area of the intake vents. In other words, the hole only needs to be as big as the combined area of your intake, since the INTAKES are the limiting factor. The second reason is that we get a lot of rainfall and I still needed to maintain the integrity of the roof. I wanted the lip on the roof surface so that even if a little water were to sneak past the seal, there would be less chance of it running into the opening and damage that which is stored inside. Had I cut the hole down to the flat/low section, potential airflow would not have been improved (because air can only exhaust as fast as it can come in through the intake openings) and I would have run the risk of a leaking roof. Thanks for watching.

[@naterchapman1871]

@@facilitiesmaintenancebyarne the size of the intakes is a good point, by the air that is coming in and mixing with moisture from inside the can, and heating up therefore expanding and increasing in volume, so keeping the intake and outake similar in volume will make the exhaust capacity inadequate, so now intake and exhaust both put a damper on ventilation, as for the water leaks, simply leave tabs on the lower sections of roof when you cut the hole so in effect the raised section of roof will have a bigger hole, bend them up to make dams against water intrusion under your seal. also i suggest you increase the size of your intake. the whirly bird with no intake capacity is akin to high flow exhaust on your car but keeping a very restrictive factory intake, its almost pointless, or at least not coming anywhere near its potential, which begs the question, what's the point?

[@facilitiesmaintenancebyarne]

@@naterchapman1871 I applaud your enthusiasm and appreciate the interaction however, as a certified commercial/residential building inspector for nearly 2 decades, I do know how this works. To respond to your points, I doubled the original number of intake vents. I never said the intake/exhaust were similar in volume capacity - the exhaust size is greater. Warm air rises and facilitates convection. And finally, the "system" is working; over the last 7 months I have noted a vast improvement in humidity levels to the point where it is no longer a concern.

[@naterchapman1871]

​@@facilitiesmaintenancebyarneiv been in construction for 25 years, I have taken the internatchi home inspection training, no offense but honestly I would not trust the "expertise" of many home inspectors.